Older drivers' crash rates decline unexpectedly

Contrary to expectations, senior drivers aren't causing more crashes than they used to. Nor are they dying more often in crashes, even though they hold onto their licenses longer. In fact, the rate of fatal crashes per licensed driver 70 and older declined from 1997 to 2008. Rates of less severe crashes reported to police officers went down, too.

These declines weren't anticipated. Nine years ago Institute researchers, noting the growing proportion of the U.S. population represented by people 65 and older, expressed concern about the risk (see "Older drivers aren't dangerous except maybe to themselves," Sept. 8, 2001). Older people's high crash rates when they drive, together with their increase in driving, indicated a problem might be emerging. But it hasn't emerged, at least not yet.

The explanation isn't simply that an ailing economy is reducing crashes, deaths, and injuries. This is true as far as it goes, but the economy is influencing miles driven and crash rates among people of all ages. It doesn't explain the disproportionate decrease in the crash rates of older drivers versus middle-age people during 1997-2008.

At least a partial explanation may be that older people are policing themselves. The ones who need to curtail driving, or stop altogether, may be doing so on their own (see "Older drivers' fatal crashes trend down," Dec. 27, 2008). A new Institute study points to state licensing policies that can reinforce these self-imposed limitations.

Older versus middle age

About 28 million people in the United States were 70 and older in 2008. About 78 percent of them had driver's licenses, up from 73 percent of 24.4 million older people in 1997. At the same time, fatal passenger vehicle crashes per licensed driver in this age group fell about 37 percent, a new Institute study reveals. The most dramatic decline was among drivers 80 and older, whose fatal crash rate went down by almost half. In contrast, the rate among drivers 35-54 years old dropped 23 percent.

"If the crash trends of drivers 70 and older had mirrored the experience of middle-age drivers, we estimate that about 10,000 additional older drivers would have been in fatal crashes during 1997-2008," says Anne McCartt, Institute senior vice president for research and an author of the new report. Most of the additional deaths would have been among drivers 80 and older.

Crash risk and odds of survival

To separate the possible contributions of crash risk versus surviving a crash once it happens, Institute researchers focused on collisions of all severities in 13 states that provide a reasonably representative sample of the U.S. population of older drivers and crash profiles. A main finding is that injury crash rates declined 34 percent among drivers 80 and older from 1997 to 2005. This compares with a 16 percent decrease among 35-54 year-olds.

The rate of police reports on crashes involving property damage but no injuries went down 20 percent among the oldest drivers while staying about the same among people 35-54 years old. At the same time, the odds of an older person surviving a crash are on the increase. Researchers calculate that a driver 70 or older is about 3 times as likely as someone 35-54 years old to sustain a fatal injury in a crash. This ratio, based on 2005 data, is down from 3.5 in 1997.

"Trends for older drivers are improving both ways," McCartt explains. "Seniors are less likely to get into police-reported crashes in the first place, and they're less likely to die from their injuries when they do crash. This isn't what we expected, given driver demographics and other influences."

Licensing provisions for older drivers

States can impose restrictions as drivers age, and some jurisdictions have been doing it for years (see Status Report special issue: older drivers, March 19, 2007). As of last month, 18 states shorten the license renewal period. Vision tests are required for older drivers at every renewal in 9 states and road tests in 2. Older drivers in 7 states are prohibited from renewing licenses by mail or electronically.

Programs in Iowa identify potentially unfit drivers and administer road tests. The license of a driver who doesn't pass the test may be suspended, although more often the result is a restricted license that prohibits driving at specified times or places.

Institute researchers interviewed more than 500 people 70 and older in Iowa shortly after they renewed their licenses, finding those with state-imposed driving restrictions older and generally more impaired in terms of vision and physical mobility than drivers who didn't have to take the road test or who passed it. Many of the drivers with restricted licenses already were limiting their own driving at night and on high-speed roads.

Six-month follow-up interviews revealed that most restricted drivers were in compliance. They had decreased their weekly mileage more than unrestricted drivers and reduced driving at night and on high-speed roads.

"With or without state action, it looks like older people are doing a good job of addressing their own driving abilities," McCartt says. "This may be a reason we're not seeing the increases in older driver crashes and crash deaths that were anticipated a few years ago."

Another reason might be improvement in older people's health and physical conditioning. This could be reducing their risk of crashing and helping them fare better when they do crash. Older people may be benefiting more than younger motorists from vehicle crashworthiness improvements. They may be surviving crashes more often because of enhanced emergency medical services and trauma care.

The population of older people is growing. People 70 and older are holding onto their licenses longer than they used to. At the same time, their crash risk is declining more than it is for middle-age drivers. This isn’t simply because an ailing economy is reducing crash risk. It may be that older people are restricting their own driving. State licensing policies can reinforce the self-imposed limitations.